Fitting zg flares on rear- determining flare height

[fusion]

I am in the early stages of fitting my rear ZG flares on my 280z.  I have read through a lot of install threads, most of which have broken picture links.  My understanding is the best way to decide how high up to mount the flares is to remove the spring from my BC racing coilover to allow the shock to compress all the way to the bump stop.  

 

However, when I did that, I can only compress the shock up so far until the rear wheel/tire (275-50-r15) runs into the factory wheel arch.  There is still a ways to go before the bump stop bottoms out.  But it's extremely hard to measure the distance remaining.  It's a chicken-and-egg scenario.  I can't determine where to make my cut line until I can compress the wheel/tire all the way, but I can't do that without cutting the metal first.

 

I must be missing something, any thoughts?

Edited October 5, 2021 by fusion

[fusion]

Anyone?

[calZ]

Cut just enough that you can bottom the shock and then trim more afterward? 

[fusion]

That's basically what I was thinking.  But all the images I've seen seem to show everyone making just one cut.

 

 

[Onesight1]

pretty sure the fender top covers over the body line, but just teeny bit

[JMortensen]

Looks like Onesight1 and I are late to the party, but I think the main thing is that you want the suspension to have as much bump travel as possible and simultaneously want the rear tires to not hit the insides of the fenderwells. If you line the flares up with the bodyline like most do, then you will not have enough clearance for the tire, particularly if you have taller tires or run the car lower, or both. Taller tires and lower ride height seems to be the thing to do these days. 

Mounting the flares high enough to allow for the tire to move means installing the ZGs at a pretty awkward height, unfortunately. John Coffey had a good thread 20 years ago about Amir's SR20DET powered Z, and how he had to move the flares up to keep it from eating tires. I also shared my experience cutting and then redoing it to get enough clearance for 24" slicks with gigantic IMSA flares. 

I don't remember whose car this is, but it's an example of what NOT to do IMO.

[fusion]

Thanks for the comments.  I understand about having enough space so the tires don't bottom out.  My question is how do you determine where to cut, when the tires hit the factory sheet metal before I can reach the bump stop.

[JMortensen]

I assembled the suspension without springs, used a ratchet strap around the A arm to compress, then I think I measured from the hub to the fender.